In general, although floodlights, landscape lighting lamps and advertisement lamps have been occupied by various light sources such as fluorescent lights, neon lights and halogen lamps, the recent trends are that LEDs (Light Emitting Diodes) have come into limelight as light sources in these fields. The reason of the LED being focused as a light source is because of device characteristics. Although conventional light sources have used mercury for illumination, the LED has advantages in that the LED is environment-friendly with reduced upkeep due to less power consumption and with a long life and excellent in durability and strong over the conventional light sources. Furthermore, usage of LEDs is accelerated due to advantages such as gradually increased luminance and light emitting efficiency and no fear of electric shock because of driving in a low voltage.
Even if waterproof floodlights using LEDs for illumination are manufactured, limitations are incurred in manufacturing the waterproof floodlights according to manufacturing method of heat dissipating portion attached with a lighting portion including the LED. The heat dissipating portion is generally manufactured by a die casting method and an extruding method. The die casting method is advantageous of no limit to shapes to allow forming a 3D heat dissipating portion, but disadvantageous of reduced heat dissipating efficiency over a heat dissipating method. Although the heat dissipating, method is higher than the die casting method in terms of heat dissipating efficiency, the heat dissipating method suffers from disadvantages in terms of formation of a shape due to the fact that it can form a heat dissipating portion only in 2D instead of 3D.
Furthermore, even if a heat dissipating portion is manufactured by any method of die casting method or extruding method, both methods suffer from drawbacks that require separate packing for preventing introduction of moisture into the heat dissipating portion. FIG. 1 illustrates a waterproof floodlight (100) manufactured by die casting method, where the waterproof floodlight (100) provides a packing (130) coupled between a cover (120) and a heat dissipating portion (110). There are cases where a sealing is additionally formed near the packing (130) in order to obtain a double waterproof effect. However, the method illustrated in FIG. 1 suffers from disadvantages in that a heat dissipating portion, a cover and a packing must be of very high quality and the defect generation probability is very high in the assembly process.
A technology of mounting a packing inside a cover has been developed in order to solve the aforementioned disadvantages/problems. Referring to FIG. 2, Korea Laid-Open Patent No. 2012-0013681A discloses a waterproof and heat dissipating LED module. The LED module (200) includes a heat dissipating portion (210) attached and coupled to a substrate (220) mounted with an LED, a substrate (200), and a protective cover (240) of the substrate, where an O-ring (230) for waterproof is mounted between the substrate (220) and the cover (240), whereby waterproof function by an outside cover (240) and a waterproof function by an inner O-ring are performed.
However, the Korea Laid-Open Patent suffers from disadvantages in that assembly is cumbersome and inconvenient because a separate configuration (O-ring 230) such as padding must be included even if double waterproof function is implemented. Furthermore, even if an inner padding is included, a problem still exists because a small but fine gap exists between the cover and the inner padding to introduce moisture into the waterproof and heat dissipating LED module. Thus, waterproof floodlights are required that need a simple assembly process and perfect sealing using a minimum configuration only.